An example of a dense wavelength division multiplexer (DWDM) module is disclosed in a co-pending patent application, U.S. Ser. No. 10/022005, filed on Nov. 30. 2001, which is incorporated herein by reference.
1. Field of the Invention
This invention relates generally to a DWDM module and more particularly to a DWDM module which has an excellent seal and which is easy to manufacture.
2. Description of the Related Art
DWDM systems are widely deployed in modern communications networks. In a DWDM system, multiple channels are carried over a single optical fiber without interference between the channels, so that channel-carrying capacity is increased. A DWDM system includes a DWDM module that secures a plurality of DWDMs therein. DWDMs must be properly secured in the DWDM module, to ensure reliability and durability of the DWDM module. Various means have been developed for securing DWDMs.
A conventional DWDM module uses epoxy to secure DWDMs therein. Heat must be applied to the epoxy to cure it. This is time-consuming, generally 2 or 3 hours at a temperature of 110 degrees) and the epoxy resin degrades and loses its adhesive quality if exposed to changing in environmental conditions.
Thus for this and other reason, it is desired to provide an inexpensive DWDM module which is has excellent hermetic seal to provide a more stable environment for the DWDMs.
An object of the present invention is to provide a DWDM module which has an excellent hermetic seal to secure the stability of the DWDMs received therein.
In order to achieve the above object, a dense wavelength division multiplexer (DWDM) module according to the present invention includes a housing, a retainer, a plurality of DWDMs, a cover, a gasket ring and a front seal. The retainer is fixed in the housing and receives the DWDMs therein. The front seal is fittingly and tightly received in a front side of the housing. The gasket ring is pressed into a recess top of the housing. The cover engages with the top of the housing and presses against the gasket ring. Therefore, a tight hermetical seal is formed in the DWDM module.
Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of a preferred embodiment of the present invention with attached drawings, in which: